1. Field of Invention
The present invention relates to a fastener, and more particularly to a string fastener for a person to secure the string.
2. Description of Related Art
With using conventional shoelace, a person who wears shoes must tighten the shoelace to prevent the shoelace from being loosed. Otherwise, the person may trip over the loosed shoelace and the potential hazard may occur. Thus, the person needs to squat down to tie the loosed shoelace again. However, tying the loosed shoelace in crowd or during exercise takes time and is also inconvenient for the person. As a result, a fastener for securing the shoelace has been developed.
The conventional shoelace fastener is a spring-biased structure. This fastener comprises a plastic sheet and a spring. The spring pushes the plastic sheet against the shoelace with the fastener case to hold the shoelace in position. Therefore, the tightening and positioning effects are generated.
However, the user needs to spend much strength to against the elasticity of the spring when the elasticity is large. Correspondingly, the tightening and positioning effects are reduced when the elasticity is small. When the spring force is weak, relative slipping may occur between the shoelace and the plastic sheet if the fastener is pulled or drew. Therefore, an enhanced shoelace fastener is required to overcome the poor positioning of the conventional spring shoelace fastener.